This invention relates to the fastening of structures together, and in particular to a fastener approach useful for fastening an electronic device to a support and heat sink.
An electronic device that produces heat during operation may be cooled to prevent overheating of the electronic device. To achieve the necessary cooling, in one approach the electronic device is supported on and fastened to a heat sink. The heat sink conducts away the heat produced by the electronic device, maintaining the electronic device within an operating temperature range.
To achieve the most efficient heat removal performance, the electronic device should be in good thermal contact with the heat sink. If there is an air gap at the interface between the electronic device and the heat sink, the air gap will serve as an insulator and an impedance to the heat flow. A close contact between the facing surfaces of the heat sink and the electronic device is therefore desirable.
A number of approaches are known for attaching the electronic device to the heat sink so as to achieve good thermal efficiency at the interface. For example, the articles may be joined by mechanical fasteners at their peripheries, but any deviation from planarity in the facing surfaces will lead to thermal inefficiency. The articles may be brazed together with a brazing alloy between the articles. This approach requires that the articles be heated above the melting point of the brazing alloy, which may not be acceptable for some types of electronic devices. The articles may be joined with a thermally conductive adhesive, such as a carbon-filled or metal-filled curable adhesive. The thermal transfer rates through available thermally conductive adhesives are rather poor, reducing the efficiency of the thermal conduction process. With some of these approaches, the electronic device cannot be later separated from the heat sink for rework, repair, or other reasons. Thus, while operable techniques are available, there is opportunity for improvement.
There is a need for a better approach to joining two articles together to achieve both mechanical fastening and good thermal conductivity between the articles. The present invention fulfills this need, and further provides related advantages.